To surely fix a frequency through an original channel without increasing the cost of equipment and to enable stable communication by selecting and fixing the reception frequency of highest electric field strength among received signals at the allocated reception frequencies.
A radio reception part 2 demodulates a received high frequency signal at the frequency designated by a reception channel setting part 3 and sends that signal to a data decoding part 4. A field strength measuring part 7 measures the field strength of the received signal and transmits that information to the data decoding part 4. At the data decoding part 4, equipment identification information set by an equipment identification information setting part 5 is compared with equipment identification information contained in the received signal and when that information shows the side of a communicating party, the measured field strength data are temporarily stored in a data storage part 8 together with that reception channel frequency. The reception channel setting part 3 designates and fixes the channel frequency of highest field strength in these data.
ONO TAKATOSHI
SADA NORIBUMI
SAKUMA TSUTOMU
